Speedboat



J. S. MASON Jam 24% WW) SPEEDBOAT 5 SheetsSheet 1 Filed March 19, 1946 JOHN $.MP3SQN J. S. MASON Jams 24, W$

SPEEDBOAT 3 Sheets-Sheet 2 Filed March 19, 1946 JOHN S. MfXSQN J. S. MASON SPEEDBOAT Jam. 24, W54) 5 SheetsSheet 3 Filed March 19, 1946 ate-mated Jan. 24, 1950 NITED STATES PATENT OFFICE SPEEDBOAT John S. Mason, Columbus, Ohio Application March 19, 1946, Serial No. 655,522

8 Claims. l

This invention relates to an improved arrangement of supporting planes on a speed boat which will give it greatly increased stability without any loss in efficiency.

Speed boats have been developed to the point that they will ride across the surface of the water as efiiciently as land vehicles will travel on land. These boats would be an equally practical means of transportation except for the fact that they are extremely unstable and likely to overturn.

It is the purpose of this invention to eliminate this instability without sacrificing any efficiency. In the development of speed boats, it has been found that the most efiicient means of support for a fast moving boat is the simple inclined planing surface which is exemplified by the aqua plane or barn door moving across the water with a man standing on it. In its most efficient condition, it is a fiat surface moving across the water at an angle of attack of from two to six degrees to the surface of he water and with only its after section in contact with the water. Its carrying capacity is determined mainly by its width and the speed at which it moves, and is only slightly affected by its submerged length. The resistance created by the planing surface decreases as the speed increases up to a point and then becomes constant. It decreases because, as the speed increases, it climbs out of the water leaving less surface in the water to cause resistance. It becomes constant when, with the increasing speed, the skin friction is increasing at the same rate as the wetted area is decreasing. It reaches this balance when the plane approaches its top designed speed. This constant resistance, for an efficient plane, is of the same order of magnitude as the resistance offered by the wheels of an automobile. If the plane is arranged on the boat so that its load center is directly over the after edge of the plane, the plane will approach the state of riding on a theoretical line of contact and be in its most eiiicient state. It will never reach a theoretical line of contact, but will approach it to the point of drawing an eighth of an inch of water or less.

These phenomena are explained by the simple physical theory of reactive forces. As the plane passes across the water, particles of water are deflected downward by its inclined surface and are given an acceleration which reacts as a force normal to the surface of the plane. Since the plane is inclined to the line of motion of the boat, this force has a horizontal and vertical component. The horizontal component being resistance to the motion of the boat and the vertical component being lift. Since the particles of water are only accelerated at the point of contact and thereafter continue downward across the face of the plane at constant speed, the reactive force theoretically only occurs at the point of contact. Therefore, theoretically the plane would climb out of the water until it only contacted it at its after edge. Actually, certain inertia of the water causes the reactive force to spread over a small area of the planes surface, dissipate almost completely in a very short distance, perhaps two inches, and finally dissipate completely throughout the rest of the wetted length of the plane.

It is obvious that the most eificient boat would be one whose load is centered directly over the after edge of the planing surface. The resulting instability can be eliminated by moving the load forward and allowing a large portion of the plane to drag aft of the line of lift, but at a terrific cost in efiiciency. Or it can be eliminated with no loss of efliciency by using more than one plane and placing the load at the dynamic center of their after edges, thereby allowing each plane to carry its portion of the load directly over its after edge and providing a wide base of support by the pattern of planes.

My invention provides a new arrangement of planes which eliminates the difficulties heretofore encountered and accomplishes complete stability without loss of efiiciency. It consists of a hull of any convenient design to which is attached a pair, or pairs of opposed planing surfaces, which converge towards the bow, extend the whole, or

a large portion of the boats length, are outwardly and oppositely inclined to the surface of the Water, and whose lower edges are below the bottom of the boat.

The invention consists of certain novel features of construction and combinations of parts which will be hereinafter described and pointed out in the claims.

In the accompanying drawings:

Figures 1 and 2 are diagrammatic views in perspective to illustrate the principles of the invention;

Figure 3 is a view in side elevation of Figure 1 illustrating the distribution of the supporting forces along the lower edges or lines of lift for the planes.

Figure 4 is an end view illustrating further the principle set forth in Figure 3;

Figures 5 and 6 are views in to plan and side elevation respectively, showing the invention applied to a speed boat. 1

Figure 7 is a detail sectional view through one of the converging planes showing how it may be tapered.

The geometrical arrangement of these planes is depicted in Figures 1 and 2. The hull is indicated by the rectangular block l9. The planes are shown as I3 and M. They are attached to the hull by outriggers H and I2. They converge towards the bow at the angles A. They are outwardly and oppositely inclined to the surface of the water at the angles B. Their lower edges are below the bottom of the boat. By reason of the angles at which the planes are set the lower edges become the lines of lift. That is, as the boat traverses the water with the velocity V, the planes provide dynamic lift and raise the boat completely out of the water so that it is supported entirely by the planes and the planes are only contacting the water along their lower-edges ab. The planes pass across the water disposed in an inclined and diagonal position with respect to the hull H]. The angle of attack of the planes is the angle C in Figure .1, which is the angle of intersection of a vertical plane parallel to the line of motion with the planing surfaces l3 and M, and the waters surface. It is the geometric resultant of compounding the angles A and B. Since there is one most efficient angle of attack somewhere between two and six degrees, the angle .C :isset as a design pecification and the angles A and B are varied to arrive at the correct angle C. The angle A can be varied from almost ninety degrees to almost zero. If it were ninety degrees, the plane would be the conventional, or barn door type. the plane would afford -no lift. For a given angle 0, angle B will approach ninety degrees as angle A approaches zero. Experiments with boats of this design indicate that the most efficient combination is to make angle A equal to angle C in which case angle B is forty-five (45) degrees.

The manner in which the forces act on these planes is shown by the vector diagram of Figure 1. A particle of water strikes the plane, is accelerated downward and the result is the pressure P which is a force normal to the plane. This force resolves into two components; the vertical force F which is the supporting force, and the horizontal force H. The force H in turn resolves into two components; the transverse force N and i the longitudinal force R which is the resistance to the forward motion of the boat. The force N is neutralized by a corresponding force on the opposite plane. The resulting efiective forces are the lifting force F and the resisting force R.

Figures '3 and 4 show the distribution of the supporting forces along the lower edges .or lines of lift of these planes. The lower edges, ab of the planes are shown below the bottom .01. the boat and are the lines of contact with the water. The supporting forces described above are distributed along the whole length of the edges ab, thereby, affording support to the whole length of the boat and at the outer extremities of its width. The supporting forces .being so distributed the boat is carried on a large base and is afforded great stability by it.

The stability of the boat is further increased by the behavior of the planes when changing course as shown in Figure 2. When the boat changes course it rotates its center line away .from its previous line of motion and tends to continue along it previous line of motion or slide sideways. lt is only its greater natural resistance :to sideward motion which makes :it change course.

If it were zero,

This resistance ordinarily takes the form of a force that will overturn the boat. In the case of this boat, however, another force is derived that counteracts the overturning forces and prevents the boat from overturning. In Figure 2 the vectors, VI3 and VM indicate the velocities of the two planes. since the boat is changing course, its centerline is no longer parallel to these velocities and the velocities are of different magnitudes. The plane on the outside of the turn is moving faster than the inside plane. Also, since the boat is moving sideways, the angles A and C are changing and are different for each plane. In the diagram the boat is turning to its right and Aid has increased while A53 has decreased to a minus value. Consequently, CM is greater and CIS is a minus quantity. The result being that FM has increased and Fl3 has changed to a downward force. In other words, the lift has increased on the outside plane and reversed to a drag on the inside plane, completely counteractin the overturning forces. The stabilizing forces are accentuated further by the fact that the outside plane is moving faster than the inside plane. The stability is further enhanced by the fact that the resistance of the outside plane, RM is greater than that of the inside plane Rl3. This tends to set the boat on its previous course when the controls are released.

The stability of this boat is not lost when passing over waves. By reason of the distribution of the supporting forces along the whole length of the boat as described in Figure 3, the boat is always supported at several parts of its length. This prevents the boat from diving and leaping, or porpoising, as would the conventional boat whose planes are alternately left unsupported when they pass over the waves.

Figures 5 and 6 show a practical application of the planes to a boat. In this case one pair of planes is used and they extend the whole length of the boat furnishing its entire support. In other applications, more than one pair can be used and they can be used in conjunction with other types of planes or foils. They can extend over any part of the length or beyond it. This application shows them attached directly to the sides of the boat rather than by Outriggers. They are vented at the bow and along their attachment to allow air into the void under the boat and to allow water to escape when changing course and the inside plane is digging in. The boat using these planes can be designed of all flat surfaces without aifecting its hydrodynamic qualities all and without aiiecting its aerodynamic qualities appreciably. Being all flat surfaces it can be constructed very economically of sheet materials.

A conventional type of plane is shown on the bottom of the hull it of the boat and is disposed between the pianes l3 and it. This type of plane l5 may be employed with certain types of boats and omitted in other instances. The requirements of the boat will govern the number of these planes 5 to be used or omitted. Also, the dimensions of the boat will govern the number of planes l3 and I l that may be employed, as in some instances several pairs might be required.

In Figure 5 a prime mover or engine :6 is indicated connected to a suitable propeller H for driving the boat, which in this instance is preferabiy a speed boat. The size or character of the engine and propeller is naturally governed by the size and character of the boat, but which must be adequate to drive the boat at speeds to warrant the planes I3 and M to support the hull on the water.

With the present construction the lower edges of the planes extend below the bottom of the hull and afford a supporting force evenly distributed along the whole length of the boat. The planes are disposed at such a distance apart as to provide a wide base of support and prevent the boat from overturning, and are of such length as to span any waves normally encountered. Also, by the disposition of the planes so that they converge from the stern towards the bow of the boat and inclined outwardly and oppositely to waters surface allowance is afforded for complete freedom of design of the hull and the distance between the two planes, as well as to the specific manner of attaching the planes to the sides of the hull.

I claim:

, 1. In aspeed boat, the combination of a hull provided with means for propelling the same, and a pair of supporting planes attached to the sides of said hull and converging towards the bow of said hull and inclined outwardly and oppositely to the waters surface, and means for supporting said planes in spaced relation to said hull to allow free passage of water around said planes and to present the outer and inner inclined surfaces of said planes to the action of the water to provide both lifting and stabilizing forces to the boat in its various movement through the water.

2. In a speed boat, the combination of a hull provided with a power propelling means, and a pair of supporting planes attached to the sides of said hull and converging towards the bow of said hull and inclined outwardly and oppositely to the waters surface, said planing surfaces having their lower edges projecting below the bottom of said hull and means for supporting said planes in spaced relation to said hull to provide for venting air and water between said planes and said hull during forward and turning motion of said boat.

3. In a speed boat, the combination of a hull, and a pair of supporting planes attached in spaced relation to the sides of said hull and converging from the stern of said hull towards the bow thereof and inclined outwardly and oppositely to the waters surface, said planing surfaces having their lower edges extending below the bottom of said hull.

4. In a speed boat, the combination of a hull and a pair of supporting planes disposed adjacent the sides of said hull, and having the lower edges thereof extending below the bottom of said hull, outriggers disposed between said hull and planes for supporting said planes and spacing said planes with respect to said hull, said planes converging from the stern of said hull towards the bow thereof and inclined outwardly and oppositely to the waters surface.

5. In a speed boat, the combination of a hull provided with power propelling means, and a pair of supporting planes attached to the sides of said hull and converging towards the bow of said hull and inclined outwardly and oppositely to the waters surface, said planing surfaces having their lower edges projecting below the bottom of said hull and means for supporting said planes in spaced relation to said hull to allow free passage of Water around said planes and to present the outer and inner inclined surfaces of said planes to the action of the water to provide both lifting and stabilizing forces to the boat in its various movement through the water, and a plane on the bottom of said hull and disposed between said converging planes.

6. In a speed boat, the combination of a hull provided with power propelling means, and a pair of supporting planes attached to the sides of said hull and converging towards the bow of said hull and inclined outwardly and oppositely to the waters surface, said planing surfaces having their lower edges projecting below the bottom of said hull, and means for supporting said planes in spaced relation to said hull to present the outer and inner inclined surfaces of said planes to the action of the water to afford a lift in a forward direction of travel of said boat and stabilizing forces in changing the boats course, one of said planes having its outer inclined surface affording a support in the changing of the boats course, and concurrently said other plane having its inner inclined surface acting as a drag or downward force, and said planes combined creating a moment of force counteracting the overturning of said boat.

7. In a speed boat, the combination of a hull with a pair of supporting planes attached to the sides of said hull and converging towards the bow of said hull and inclined outwardly and oppositely to the waters surface, said planing surfaces having their lower edges projecting below the bottom of said hull and presenting their inner inclined surfaces to the action of the water simultaneously with their outer inclined surfaces.

8. In a speed boat, the combination of a hull, a pair of supporting planes disposed along the sides of said hull and converging towards the bow of said hull and inclined outwardly and oppositely to the waters surface, and means for attaching said planes to said hull to provide venting between said planes and said hull and presenting the inner and outer inclined surfaces of said planes to the action of the water.

JOHN S. MASON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,637,677 Bonnemaison Aug. 2, 1927 2,257,406 Von Burtenbach Sept. 30, 1941 2,344,619 Lake Mar. 21, 1944 2,373,019 Dix Apr. 3, 1945 

